Exploding Fullerenes Could Benefit Future Medical Therapeutics

For the first time, scientists have demonstrated that functionalized fullerenes heat, ignite, glow, and transform into other carbon nanostructures, such as carbon nanotubes, when they are exposed to low-intensity laser light. As reported in Nanowerk, this discovery could have implications for future medical device technology, especially in the area of cancer therapy.

"We have shown that certain functionalized fullerenes, including polyhydroxy fullerenes--which are known to be environmentally safe and to have therapeutic properties--are heated or ignited by exposure to low-intensity continuous-wave laser irradiation," remarks Vijay Krishna, a postdoctoral associate at the Particle Engineering Research Center at the University of Florida (Gainesville). "We also show that polyhydroxy fullerenes and other functionalized fullerenes can be transformed into single-walled nanotubes, multiwalled nanotubes, and carbon onions without the presence of a catalyst by exposure to low-intensity laser irradiation in an oxygen-free environment."

Using intensities as low as 1 x 10² W cm^-2, Krishna, together with team leaders Brij Moudgil and Ben Koopman, has ignited fullerenes using near-infrared (785-nm), green (540.5-nm), and blue (488-nm) laser radiation. The threshold laser intensity for ignition and the heat generated in the presence of atmospheric oxygen depend on the type of functionalization.

In addition to a range of potential nanotechnology, sensor, and industrial applications, the researchers believe that their findings could benefit cancer therapy by providing a safe, biocompatible target for photothermal ablation. "The photothermal and photoacoustic properties of carbon nanotubes make them attractive for cancer therapy, but they are not biodegradable and accumulate in certain organs such as liver and spleen," Krishna tells Nanowerk. "Polyhydroxy fullerenes have the same therapeutic properties and in addition are biocompatible and are rapidly eliminated--polyhydroxy fullerenes are 1.3 nm in size, which is below the renal filtration limit of 5.5 nm."

For more information, see "New Fullerene Discovery Sparks Research Into Medical And Industrial Applications."